Methods for investigating wells



Sept. 29, 1959 M. P. LEBouRG METHODS FOR INVESTIGATING WELLS 2 Sheets-Sheet 1 Filed May 1e. 1955 lECORDER FIG. 4

fr. x2.: l,

INVENTOR. MAURICE P. LEBOURG. BY www HIS ATTORNEY.

Sept. 29, 1959 M. P. LEBOURG 2,906,944

METHODS FOR INVESTIGATING WELLS Filed May 16, 1955 2 Sheets-Sheet 2 5r FIG.5A FIG. 6A

j 50 v, y 55 I 57 59 $7 Y 4 56 \sl 5 sa l 1 FIG. 5B F|G,6 B

INVENTOR. MAURICE P. LEBOURQ.

-BYWAQM His ATTORNEY.

nited States Patent Thisl invention: relates.l to methods: for investigating wells and; more" particularly,A pertains tofnew' andi improved methods' for obtainingy indicationsv to" facilitate y the positioning of elements along a tubular member traversing a well drilled into the earth.

Varioustypes of completionl systems are presently employed in producing hydrocarbons from` wells Certain-of thesesystems require the use' of' atleast` one valve positionedv at a considerableV depth;` along' the tubing set in the well.. For instance, gasllift'- equipmentfncludes a plurality of valves distributed alongthe' tubing for selectively effecting uid' communication: between the' tubing andthe annulus delinedl by: the'tub'ing andthe casing. These valves, for example, maybe' set in' pockets offset within' the tubing, and in` certainv case'srtheymay be retrieved' and resetthrough: the' use' of a Vspecial tool run on a wire line. v

Although retrievable valves have proven to be av desirable feature in gas-lift systems,v itl is often-di'cult for the operator to be certain that ai valve hasbeen properly set in its pocket; Moreover, experiencehas shownl that in some cases where the' valve has notbeen properly set, it may fall tothe bottom ofthe well. In-ad'dition, throughv an operating error, a valve'calib'rated toaprecalculated` pressure may be' set ini the wrongl pocket.

Another variety of well: completion equipment includes an internal sleeve valvethat may be shiftedby a wire line tool to establish,. or shut olf, communication between theY tubing andthe casing. Here, it is' not always possible to-.ascertain whether thel sleeve has been properly shifted into one of its two operating positions.

It is, therefore, an object' off the present' invention to provide new and improved methods for' locating anomalies, such as valves, and/or valvel pockets, or elements' of valves, distributed` alongl the tubing which traverses a1 well.

Another object of the' present invention is to provide a. newv and improved: method for ascertaining whether a valve has-been properly set in?. al pocket in the tubing of a: gas-lift oil production system;

A further. object' of the present invention is to provide a new and improved method' for determining whether the correct valve has been set' in a particular pocket of a gas-lift system. v

A still further object ofthe present invention is to provide a: new and improved method for? determining whether a wire-line operated valve has' been properlyV actuated. f

These and other. objects of the present. invention' are attained by deriving anl electricalr signal in response to a change iny the ferromagnetic characteristics along the tubing traversing the wellandl obtaining indications` of the electrical signal as aV function of depth in the well.

-The novel features of the present invention are set forth with particularity in the appended claims. The

present invention, bothasto its organization and man-- ncrof operation;` together with further objects and advantagesthereof, may' best; be,l understoodl by. reference-l ice to. the following'. description taken'. in connection with the accompanying drawings in@ which: n

Figi.' 1 is: aview in longitudinaly cro'ss section of a portion: of gasllftf system shown in' association with apparatus for carrying out? th'emethod embodying thelpresent iii-ven'tion.V Y

Figs'. 2, 3A; 3l andi 4l illustrate" typical records which may be obtained through the use of the apparatus schematically illustrated in Fig;v 1`. Y

Figs'. 5AVV and-'- 5B represent al control-sleeve-ope'rated valve,4 partly 'i'nlongitudinal cross section, shown in closed' and open conditions,-resp'ectively;` and Figs. 6A andl 6B illustrate typical records which may be obtained in accordance with the' present invention for the respective conditions of the valve shown in Figs. 5A andi 5B?. Y

InFig. of the-drawing there is shown a tubing string including sections 15'y and- 16- connected together by a threaded jointl'17- and extending downwardly throught an oil well casing 18. Of course,Y while' a great many tubing sections are usually employed so thatl the tubing string extends toa depth of several thousand-feet, for the sake ofsimplicity in tle' representation' only a limited" number of sections have been illustra-ted?, and the customary well-head-assernbly'has been` omitted. j

Threaded to the' lower endY of tubing section 16` is a mandrel 19 having anoifset" sect-ion- 20. A- valve-receiving; pocket 2T is positionedi atv the1 lower end of offset 20 and receives a` gas-liftr valve' 22', and additional tubing sections (not shown) extendI from the' lower end of mandrell 1'9". Altliougha single pocket and its co'rr'espending` valve have been illustrated, itwill be understood1 that usually -asf many as six or eightvalves are positionedLl in pocketsdistributed along the tubing string', each one calibrated t'o a precalculated pressure. The tubing sections 1'5 and: I6;- the' tubing joint 17' and the mandrel 11'94 are usually constructed of' steel, while pocket 21 is: constructed ofa corrosioniresistant material, such as an alloy of nickel and copper commonly referred to as MoneL Since Monel is' a relatively non-magnetic material compared' to steel", the locationy of pocket 21` may be determined by running a device responsive to' magnetic properties through thev tubing string andthe mandrels. For example, ahousing 23' enclosing a casing collar' locator', for example, of the type' described in Patent' 2,515 V8,427v is' supported* by a cable 24 so that it may be lowered into thewelll Of course, any other lnOWn-t'ypeof reluctance-respon`sve` device may be suitably employed.` p

TheA apparatus withiirliousi'ng 23 i'sconnected vvia insul'ated`- conductorstnot shown) of cable 24- to a recorder 25; locatedr at the surface' ofJ the earth; The recordermay, for example; comprise a recording; voltmeter in which the' recording medium is displaced" in proportion' to movement ofthe housingthrough' the well; Thus c'ontinuous record of' magnetic' anomalies' is obtained as a function' of depth in the' well; Y

In operation, and'in accordance with the method ernbodying the present invention, the casing; collar locator 23j is lowered into' thewellu and asit passes between' tubing sections 15 and 1'6-the' ferromagnetic' anomalies producedy by joint '17 are recorded@ For example', the resulting' record may have the appearance illustrated inf Fig; 2 which is-a plot off'vol'tage as a function of depth. This record includes'y aV response 30 characterizing the" casing. joint 17'; Y Y

As th'ei casing collar locator 23i encounters the"Monel valve-receiving pocket 21', fluctuations 32'andv 33 are d'e-y rivedi VItwillbe observed that responses'fSZ and 33-have alrel'atilve spacing.' representativeof the longitudinal din'ien-V sioniofpo'cket 2.1i andthat they areeasily distinguishable' frcmmesponsetl. Consequently; theseanom'al'ies may be'-v independently identified and located as to their depth in the well. it may thus be seen that in accordance with the present invention an electrical signal is derived in response to a change in the ferromagneticcharacteristics along the tubing traversing a well and indications are obtained of the electrical signal as a function of depth in the well. Accordingly, the valve-receiving pockets may be accurately located from the surface of the earth.

In order to determine whether a valve is properly set in its pocket, the valve may be provided with a small permanent magnet at its upper end 26. Thus, as shown in Fig. 3A the record produced in response to the signal from casing collar locator 23 contains an additional undulation 34 in addition to the undulations 32 and 33 which represent the valve-receiving pocket 21. The spacing between undulations 34 and 32 providesan indication as to whether the valve is properly seated. For example, as shown in Fig. 3B, an improperly seated valve produces an undulation 34 spaced at a greater distance from undulation 32 than the spacing between the corresponding undulations 34 and 32 of Fig. 3A. Accordingly, it is obvious to the operator that the valve is not properly seated and the valve is reseated.

lf desired, the same method may be applied for properly seating blind plugs which are set in place of valves.

By using a number of small magnets spaced along the longitudinal axis of each valve, the valves may be coded in accordance with their various pressure ratings. For example, as shown in Fig. 4, the record derived in the recorder 25 may exhibit two undulations 35 and 36 for a particular valve (not shown) provided with two magnets. These are followed by undulations 37 and 38 representing the corresponding valve pocket. Further along the tubing, casing collar locator 23 may encounter another Valve (not shown) having three magnets and thereby producing undulations 39, 40 and 41 followed the undulations 42 and 43 representing the corresponding pocket. Since the pockets may be identified in their successive order along the tubing, the coding for each of the valves serves to identify it. Accordingly, an operator may ascertain whether a particular valve has been set in the correct pocket.

It is thus apparent that the method of investigating wells embodying the present invention may be employed to ascertain whether a valve has been properly set in its pocket as well as to determine whether the correct valve has been set in a particular pocket. Therefore, the uncertainty which formerly existed in placing gas-lift valves may be obviated through the use of the method in accordance with the present invention.

Obviously, the method above-described may be used to check the position of the control sleeve in an arrangement wherein a valve is set externally to the tubing. This may be accomplished in the use of a valve of the type illustrated by Fig. A where the valve is shown to comprise a tubular body 50 having upper and lower threaded ends 51 and 52 for association with well tubing. Supported within a cylindrical bore 53 of body 50 is a slidable sleeve 54 having a plurality of openings 55. In the position shown, these openings are effectively closed by the wall of bore 53, however, when sleeve 54 is shifted to the position shown in Fig. 5B, at least one of the openings 55 is aligned with a port 56 communicating with a channel 57 that extends to the outer surface of a side extension 58 of member 50.

To determine the position of the member 54 relative to member 50, a pair of small permanent magnets S9 and 60 are set into respective openings in each of these members. In the operating condition shown in Fig. 5A, the' magnets 59 and 69 are vertically spaced from one another and when the instrument 23 is run through the tubing to which member 50 is connected, recorder 25 produces a trace having two deflections V61 and 62 as shown in Fig. 6A. The spacing between these deflections represents the spacing between the magnets and thus it may be determined whether sleeve 54 is properly set at its upper position, fully closing the valve.

When the valve sleeve is in its fully open position, magnets 59 and 60 are adjacent one another, and the recorded trace exhibits only one deflection 63 as shown in Fig. 6B. Accordingly, any deviation from the fully open position will be evidenced by the appearance of a second deecti'on.

It is, therefore, evident that the method embodying the present invention may be employed to ascertain the operative conditionf of a. sleeve-operated valve. This procedure, of course, may be applied to any sleeve-operated valve, for example, of the type used to circulate between the tubing and the casing.

While particular embodiments of the present invention have been described, it is apparent that changes and modifications may be made without departing from the invention in its broader aspects, and therefore the aim in the appended claims is to cover all such changes and modifications as fall withinthe true spirit and scope of this invention.

I claim:

l. A method for establishing a selected condition of a Valve positioned along a tubular member traversing a well which comprises the steps of magnetically coding a movable portion of the valve relative to a fixed portion of the valve, displacing said movable portion toward a position for said selected condition, deriving an electrical signal representing variations in the ferromagnetic characteristics along the tubular member, said electrical signal exhibiting a response to said magnetic coding thereby denoting the relative positions of said fixed and said movable portions of said valve; and obtaining mdications of said electrical signal.

2. A method for establishing a selected condition of a valve having a control sleeve movable relative to a fixed member, said valve being positioned along a tubular member traversing a well, which comprises the steps of magnetically coding each of said control sleeve and said fixed member to exhibit magnetic anomalies spaced from one another relative to the longitudinal axis of the tubular member when the valve is in one operating condition and substantially aligned with one another when the valve is in another operating condition, displacing said control sleeve to bring said valve fom said one 0perating condition toward Said other operating condition, deriving an electrical signal representing variations in the ferromagnetic characteristics along the tubular member, said electrical signal exhibiting a response to said magnetic coding thereby denoting the relative positions of said control sleeve and said xed member; and obtaining indications of said electrical signal.

3. A method for investigating a well traversed by a tubular member having in association therewith a plurality of movable elements of well completion equipment comprising the steps of coding said elements and portions of said tubular member magnetically and distinguishably from one another, moving at least one of said elements relative to a corresponding coded portion of said tubular member, deriving an electrical signal representing ferromagnetic characteristics along said tubular member, said electrical signal exhibiting responses to said magnetic coding, and obtaining indications of said responses in said electrical signal thereby to denote the relative positions of said one element and said corresponding coded portion of said tubular member.

4. A method for locating valves spaced along a tubular member traversing a well in a gas-lift system comprising the steps of magnetically coding said valves and selected portions of said tubular member to distinguish said valves from one another 4according to selected characteristics thereof and from corresponding portions ofy saidtubular member, passing a reluctance-responsive decal signal in response to changes in magnetic reluctanceV of material adjacent said device, and producing indications of said electrical signal as a function of depth in the Well thereby to denote the relative positions of at least one of said valves and a corresponding portion of said tubular member and to identify said valves.

5. A method for locating a plurality of valves relative to corresponding valve-receiving pockets in a gaslift system disposed in a Well drilled into the earth comprising the steps of magnetically coding said valves to distinguish them from one another in accordance with individual pressure settings, magnetically coding said pockets, distributing said valves in said pockets, passing a reluctance-responsive device through the well to derive an electrical signal in response to a change in ferromagnetic characteristics, and obtaining indications of said electrical signal as a function of depth in the Well.

6. A method for positioning a valve relative to a valvereceiving pocket in a gas-lift system associated with a Well drilled into the earth which comprises the steps of magnetically coding said valve and said pocket to exhibit distinguishable ferromagnetic characteristics, placing said valve in said pocket, passing a reluctance-responsive device through the Well to derive an electrical signal in response to -a change in ferromagnetic characteristics of 6 material adjacent said device, and producing indications of said electrical signal as a function of depth in the Well thereby to denote the relative positions of said valve and said pocket.

7. A method for determining the relative positions of relatively movable elements disposed in a Well drilled into the earth which comprises the steps of magnetically coding said elements to exhibit distinguishable characteristics, displacing said elements relative to one another, passing a reluctance-responsive device through the Well to deri e an electrical signal responsive to the magnetic coding of each of said elements, and obtaining indications responsive to said electrical signal thereby to denote the relative positions of said elements.

References Cited in the fle of this patent UNITED STATES PATENTS 2,150,430 Drenkard n Mar. 14, 1939 2,228,623 Ennis Jan. 14, 1941 2,250,703 Crites et al July 29, 1941 2,259,904 McNarnee etal Oct. 2l, 1941 2,476,137 Doll July 12, 1949 2,558,427 Fagan June 26, 1951` 

